Simultaneous removal of third molars and completion of a sagittal split osteotomy: Effects of age and presence of third molars

Objetives The risk of removal of third molars (M3) during a sagittal split osteotomy (SSO) is controversial. The purpose of this study was to review our experience with removal of mandibular M3 during versus before SSO. Study Design A chart and radiographic review was completed in all patients who underwent an SSO from April 2010 until September 2014. The presence or absence of M3, degree of impaction, age, sex, and occurrence of bad splits were noted. The variables were analyzed using the Pearson χ², ANOVA, and Fisher's exact tests set to a significance of 5%. Results For the 215 patients, the mean age was 23.28 years with an increase in the incidence of bad splits in older patients (P =.013). Sixty-six (30.70%) of them had at least 1 M3 present at the time of surgery. There were 6 (2.79%) bad splits. Paradoxically, looking at the occurrence of bad splits and presence of third molar, when the data were analyzed by the number of patients undergoing the procedure, there was slight evidence of a difference (P =.073), but when the data were analyzed by the surgical site, there was a statistically significant association (P =.05). Conclusion The discrepancy between the 2 ways of analyzing the data may be related to there being double the number of observations when analyzed by surgical site and thus the analysis being more powerful.